Channel Estimation Techniques with Various Pilot Assignments for Wireless Stbc-based Mimo-ofdm Communications

Channel Estimation Techniques with Various Pilot Assignments for Wireless Stbc-based Mimo-ofdm Communications PDF Author:
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Category :
Languages : en
Pages : 80

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Channel Estimation and Performance Analysis of MIMO-OFDM Communications Using Space-time and Space-frequency Coding Schemes

Channel Estimation and Performance Analysis of MIMO-OFDM Communications Using Space-time and Space-frequency Coding Schemes PDF Author: Fabien Delestre
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ISBN:
Category :
Languages : en
Pages :

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This thesis is concerned with channel estimation and data detection of MIMO-OFDM communication systems using Space-Time Block Coding (STBC) and Space-Frequency Block Coding (SFBC) under frequency selective channels. A new iterative joint channel estimation and signal detection technique for both STBC-OFDM and SFBC-OFDM systems is proposed. The proposed algorithm is based on a processive sequence of events for space time and space frequency coding schemes where pilot subcarriers are used for channel estimation in the first time instant, and then in the second time instant, the estimated channel is used to decode the data symbols in the adjacent data subcarriers. Once data symbols are recovered, the system recursively performs a new channel estimation using the decoded data symbols as pilots. The iterative process is repeated until all MIMO-OFDM symbols are recovered. In addition, the proposed channel estimation technique is based on the maximum likelihood (ML) approach which offers linearity and simplicity of implementation. Due to the orthogonality of STBC and SFBC, high computation efficiency is achieved since the method does not require any matrix inversion for estimation and detection at the receiver. Another major novel contribution of the thesis is the proposal of a new group decoding method that reduces the processing time significantly via the use of sub-carrier grouping for transmitted data recovery. The OFDM symbols are divided into groups to which a set of pilot subcarriers are assigned and used to initiate the channel estimation process. Designated data symbols contained within each group of the OFDM symbols are decoded simultaneously in order to improve the decoding duration. Finally, a new mixed STBC and SFBC channel estimation and data detection technique with a joint iterative scheme and a group decoding method is proposed. In this technique, STBC and SFBC are used for pilot and data subcarriers alternatively, forming the different combinations of STBC/SFBC and SFBC/STBC. All channel estimation and data detection methods for different MIMO-OFDM systems proposed in the thesis have been simulated extensively in many different scenarios and their performances have been verified fully.

Signal Processing, Channel Estimation and Link Adaptation in MIMO-OFDM Systems

Signal Processing, Channel Estimation and Link Adaptation in MIMO-OFDM Systems PDF Author: Jianjun Ran
Publisher: Cuvillier Verlag
ISBN: 3867276498
Category :
Languages : en
Pages : 161

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MIMO-OFDM Wireless Communications with MATLAB

MIMO-OFDM Wireless Communications with MATLAB PDF Author: Yong Soo Cho
Publisher: John Wiley & Sons
ISBN: 0470825626
Category : Technology & Engineering
Languages : en
Pages : 458

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Book Description
MIMO-OFDM is a key technology for next-generation cellular communications (3GPP-LTE, Mobile WiMAX, IMT-Advanced) as well as wireless LAN (IEEE 802.11a, IEEE 802.11n), wireless PAN (MB-OFDM), and broadcasting (DAB, DVB, DMB). In MIMO-OFDM Wireless Communications with MATLAB®, the authors provide a comprehensive introduction to the theory and practice of wireless channel modeling, OFDM, and MIMO, using MATLAB® programs to simulate the various techniques on MIMO-OFDM systems. One of the only books in the area dedicated to explaining simulation aspects Covers implementation to help cement the key concepts Uses materials that have been classroom-tested in numerous universities Provides the analytic solutions and practical examples with downloadable MATLAB® codes Simulation examples based on actual industry and research projects Presentation slides with key equations and figures for instructor use MIMO-OFDM Wireless Communications with MATLAB® is a key text for graduate students in wireless communications. Professionals and technicians in wireless communication fields, graduate students in signal processing, as well as senior undergraduates majoring in wireless communications will find this book a practical introduction to the MIMO-OFDM techniques. Instructor materials and MATLAB® code examples available for download at www.wiley.com/go/chomimo

Iterative Channel Estimation Techniques For Multiple İnput Multiple Output Orthogonal Frequency Division Multiplexing Systems

Iterative Channel Estimation Techniques For Multiple İnput Multiple Output Orthogonal Frequency Division Multiplexing Systems PDF Author: İlhan Baştürk
Publisher:
ISBN:
Category :
Languages : en
Pages : 156

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Orthogonal frequency division multiplexing (OFDM) is well-known for its efficient high speed transmission and robustness to frequency-selective fading channels. On the other hand, multiple-input multiple-output (MIMO) antenna systems have the ability to increase capacity and reliability of a wireless communication system compared to single-input single-output (SISO) systems. Hence, the integration of the two technologies has the potential to meet the ever growing demands of future communication systems. In these systems, channel estimation is very crucial to demodulate the data coherently. For a good channel estimation, spectral efficiency and lower computational complexity are two important points to be considered. In this thesis, we explore different channel estimation techniques in order to improve estimation performance by increasing the bandwidth efficiency and reducing the computational complexity for both SISO-OFDM and MIMO-OFDM systems. We first investigate pilot and Expectation-Maximization (EM)-based channel estimation techniques and compare their performances. Next, we explore different pilot arrangements by reducing the number of pilot symbols in one OFDM frame to improve bandwidth efficiency. We obtain the bit error rate and the channel estimation performance for these pilot arrangements. Then, in order to decrase the computational complexity, we propose an iterative channel estimation technique, which establishes a link between the decision block and channel estimation block using virtual subcarriers. We compare this proposed technique with EM-based channel estimation in terms of performance and complexity. These channel estimation techniques are also applied to STBC-OFDM and V-BLAST structured MIMO-OFDM systems. Finally, we investigate a joint EM-based channel estimation and signal detection technique for V-BLAST OFDM system.

EFFECTIVE SPARSE CHANNEL ESTIMATION TECHNIQUE FOR MIMO-OFDM SYSTEM

EFFECTIVE SPARSE CHANNEL ESTIMATION TECHNIQUE FOR MIMO-OFDM SYSTEM PDF Author: Dr.Maddala Vijayalakshmi
Publisher: Archers & Elevators Publishing House
ISBN: 8119385969
Category : Antiques & Collectibles
Languages : en
Pages : 58

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Hopping Pilots for Joint Cfo and Channel Estimation in Wireless Sfbc-based Mimo-ofdm Communications

Hopping Pilots for Joint Cfo and Channel Estimation in Wireless Sfbc-based Mimo-ofdm Communications PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Optimal Pilot-aided Channel Estimation for MIMO DVB-T OFDM Systems

Optimal Pilot-aided Channel Estimation for MIMO DVB-T OFDM Systems PDF Author: Yuefeng Xu
Publisher:
ISBN:
Category : MIMO systems
Languages : en
Pages : 176

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Book Description
The need for wireless data and multimedia services promotes the development and application of many high-speed wireless communication techniques. Orthogonal Frequency Division Multiplexing (OFDM) techniques and Multiple Input and Multiple Output (MIMO) techniques have gained more and more interest in the last a few years. But there are still many key problems to be solved in OFDM and MIMO, including synchronization, channel estimation, and adaptive modulation. Channel estimation is the research target in this paper. In this thesis, we introduce an optimal Pilot-Aided Channel Estimation (PACE) algorithm. It works in Non Line of Sight (NLOS) environments with low Bit Error Rate (BER) and its computation cost is relatively small.

Subspace-based Blind Channel Estimation and Tracking for MIMO-OFDM Systems

Subspace-based Blind Channel Estimation and Tracking for MIMO-OFDM Systems PDF Author: Chao-Cheng Tu
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Semi-Blind Carrier Frequency Offset Estimation and Channel Equalization

Semi-Blind Carrier Frequency Offset Estimation and Channel Equalization PDF Author: Yufei Jiang
Publisher: Springer
ISBN: 3319249843
Category : Computers
Languages : en
Pages : 96

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Book Description
This SpringerBrief investigates the performance of semi-blind independent component analysis (ICA) based equalization and carrier frequency offset estimation approaches (CFO) for a number of orthogonal frequency division multiplexing (OFDM) based wireless communication systems. It provides a comprehensive overview of the challenges of channel equalization and frequency synchronization for different wireless systems. The authors present the wireless communication channel and system models. Key existing CFO estimation methods are reviewed, along with a number of the training based and non-training based (blind) channel estimation methods. This is followed by a study of ICA and its applications to OFDM-based wireless communication systems. Later chapters provide a detailed description of recent research on semi-blind CFO estimation and ICA based equalization approaches for various wireless communication systems including multiple-input multiple-output (MIMO) OFDM and coordinated multipoint (CoMP) systems. Semi-blind CFO estimation and equalization structures provide a spectrum-efficient and high-performance solution for high speed wireless communications. This book is suitable for postgraduate students, researchers or professionals in the area of wireless communications.